Airflow driving device having function of measuring flow rate and air conditioner with same

ABSTRACT

An airflow driving device includes an airflow-guiding member for receiving and guiding an airflow. The airflow-guiding member includes a first opening and a second opening. The open areas of the first opening and the second opening are different such that a pressure difference is generated between the first opening and the second opening. According to the pressure difference, a flow rate of the airflow passing through the airflow driving device is calculated.

FIELD OF THE INVENTION

The present invention relates to an airflow driving device, and more particularly to an airflow driving device having a function of measuring flow rate. The present invention also relates to an air conditioner equipped with such an airflow driving device.

BACKGROUND OF THE INVENTION

With rapid development of high-tech industries, various electronic devices such as computer or servers become essential in our lives. As known, the heat-dissipating efficacy of the electronic device influences the operating stability and the use life of the overall system. For increasing the heat-dissipating efficacy of the electronic device, a heat-dissipating mechanism is usually installed within the electronic device or the ambient environment to cool the electronic device.

An air conditioner is one of the common heat-dissipating mechanisms. The air conditioner is usually installed in the ambient environment of the electronic device. During operation of the electronic device, the heat generated by the electronic device causes elevated temperature of the ambient air. The heat generated by the electronic device is transferred to the air cooler, and then a cooled airflow is exhausted from the air cooler to the ambient environment to cool the electronic device.

Generally, if the air conditioner has a malfunction or the air conditioner has been used for a long time, the heat accumulated in the ambient environment fails to be effectively removed because the amount of the output airflow is insufficient. In this situation, the electronic device fails to be normally operated or even damaged. For realizing whether the amount of the output airflow is insufficient, the air conditioner is usually equipped with a mechanism of measuring the airflow amount. For example, one or more air meters are disposed in the outlet of the cooled airflow or the airflow path for measuring the airflow velocities at many detecting points. The measuring results are then transmitted to a controlling circuit of the air conditioner. By the controlling circuit, airflow velocities at these detecting points are averaged to estimate the airflow amount at the outlet or the airflow path. In a case that the amount of the output airflow is insufficient, the controlling circuit may adjust the amount of the output airflow of the air conditioner or emit a prompt signal to notify the user.

Although the uses of many air meters are effective to measure the airflow velocities, there are still some drawbacks. For example, since the airflow amount is estimated by averaging the airflow velocities at many detecting points, the accuracy of the estimated airflow amount is usually undesired. In addition, the method of realizing the airflow amount by averaging the airflow velocities at many detecting points is time-consuming. Moreover, in a case that an air conditioner is applied to a data center containing plural electronic devices, the airflow amount should be accurately and quickly obtained because the operating condition of the air conditioner needs to be adaptively adjusted to comply with a stringent heat-dissipating requirement. In other words, the uses of many air meters to measure the airflow velocities by the conventional air conditioner are not applicable to the data center.

Therefore, there is a need of providing an airflow driving device having a function of measuring flow rate so as to obviate the drawbacks encountered from the prior art.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an airflow driving device having a function of measuring flow rate.

Another object of the present invention provides an air conditioner equipped with such an airflow driving device in order to accurately and quickly measuring the flow rate.

In accordance with an aspect of the present invention, there is provided an airflow driving device of an air conditioner. The airflow driving device includes an airflow-guiding member for receiving and guiding an airflow. The airflow-guiding member includes a first opening and a second opening. The open areas of the first opening and the second opening are different such that a pressure difference is generated between the first opening and the second opening. According to the pressure difference, a flow rate of the airflow passing through the airflow driving device is calculated.

In accordance with another aspect of the present invention, there is provided an air conditioner. The air conditioner includes a casing, a heat exchanger, an airflow driving device, a first pressure-detecting device, a second pressure-detecting device and a controlling circuit. The heat exchanger is disposed within the casing for transferring heat of a first airflow and producing a second airflow. The airflow driving device is used for guiding the second airflow to be exhausted out of the air conditioner. The airflow driving device includes an airflow-guiding member with a first opening and a second opening. The open areas of the first opening and the second opening are different. The first pressure-detecting device is used for detecting a first pressure at the first opening. The second pressure-detecting device is used for detecting a second pressure at the second opening. According to the first pressure and the second pressure, the controlling circuit calculates a flow rate of the second airflow passing through the airflow driving device.

The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating an air conditioner according to an embodiment of the present invention; and

FIG. 2 is a schematic exploded view illustrating the airflow driving device of the air conditioner of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.

FIG. 1 is a schematic view illustrating an air conditioner according to an embodiment of the present invention. The air conditioner 1 is used for cooling a first airflow T1 and exhausting a cooled second airflow T2. The air conditioner 1 includes a casing 10, a heat exchanger 11, an airflow driving device 12, a controlling circuit 13, a first pressure-detecting device 14 and a second pressure-detecting device 15. The casing 10 has an inlet 100 and an outlet 101. The first airflow T1 is introduced into the air conditioner 1 through the inlet 100. The second airflow T2 is exhausted out of the air conditioner 1 through the outlet 101. The heat exchanger 11 is disposed within the casing 10, and arranged beside the inlet 100. After the first airflow T1 is introduced into the air conditioner 1 through the inlet 100, the heat of the first airflow T1 is transferred by a cooling medium (not shown) of the heat exchanger 11, and thus the cooled second airflow T2 is obtained.

FIG. 2 is a schematic exploded view illustrating the airflow driving device of the air conditioner of FIG. 1. Please refer to FIGS. 1 and 2. An example of the airflow driving device 12 includes but is not limited to a centrifugal fan. The airflow driving device 12 is disposed within the casing 10 and arranged beside the heat exchanger 11 for driving the second airflow T2, and forcing the second airflow T2 to be exhausted from the outlet 101 of the casing 10. The airflow driving device 12 includes an airflow-guiding member 120, an impeller 121 and a volute 122. The airflow-guiding member 120 is arranged beside the heat exchanger 11 for guiding the second airflow T2 into the airflow driving device 12. The airflow-guiding member 120 has a first guiding channel 130, a first opening 123 and a second opening 124. The first opening 123 and the second opening 124 are arranged in two opposite sides of the first guiding channel 130, respectively. As such, the second airflow T2 is introduced into the first guiding channel 130 through the first opening 123, and exited from the second opening 124. In addition, the open areas of the first opening 123 and the second opening 124 are different, so that the airflow-guiding member 120 has a neck-like or nozzle-like structure. Since the open areas of the first opening 123 and the second opening 124 are different (or the diameters of the first opening 123 and the second opening 124 are different), when the second airflow T2 is guided from the first opening 123 to the second opening 124, the second airflow T2 has different flow rates at the first opening 123 and the second opening 124. In other words, the air pressure at the first opening 123 and the air pressure at the second opening 124 are different from each other.

Please refer to FIG. 2 again. The open area of the first opening 123 is greater than that of the second opening 124. As such, when the second airflow T2 is guided from the first opening 123 to the second opening 124, the second airflow T2 is gradually converged. In other words, the flow rate of the second airflow T2 at the first opening 123 is lower than that at the second opening 124, so that the air pressure at the first opening 123 is lower than the air pressure at the second opening 124. In some embodiments, the open area of the first opening 123 is smaller than that of the second opening 124. As such, when the second airflow T2 is guided from the first opening 123 to the second opening 124, the second airflow T2 is gradually diverged. In other words, the flow rate of the second airflow T2 at the first opening 123 is higher than that at the second opening 124, so that the air pressure at the first opening 123 is higher than the air pressure at the second opening 124.

Please refer to FIG. 2 again. The impeller 121 is arranged beside the airflow-guiding member 120. The blade of the impeller 121 is driven by a motor (not shown). The impeller 121 has a second guiding channel 125 and plural lateral channels 126. After the impeller 121 is arranged beside the airflow-guiding member 120, the second guiding channel 125 is aligned with the second opening 124 for receiving the second airflow T2 coming from the second opening 124. The lateral channels 126 are disposed in the periphery of the impeller 121. As such, when the blade of the impeller 121 is driven to rotate by the motor, the second airflow T2 within the second guiding channel 125 will be exhausted out of the impeller 121 through the lateral channels 126.

Please refer to FIG. 2 again. The volute 122 includes a receptacle 127, a third opening 128, an airflow path 129 and a fourth opening 131. The fourth opening 131 is arranged at a first side of the volute 122 and in communication with the receptacle 127. The size of the fourth opening 131 matches the size of the impeller 121, so that the impeller 121 could be inserted into the receptacle 127 of the volute 122 through the fourth opening 131. The third opening 128 is in communication with the receptacle 127 and the airflow path 129. After the impeller 121 is accommodated within the receptacle 127 and the blade of the impeller 121 starts rotating, portions of the lateral channels 126 are in communication with the third opening 128. As such, the second airflow T2 coming from the lateral channels 126 is introduced into the airflow path 129 through the third opening 128. Meanwhile, the second airflow T2 exhausted out of the third opening 128 is perpendicular to the second airflow T2 coming from the second guiding channel 125. The airflow path 129 is directed to the outlet 101 of the casing 10, so that the second airflow T2 is guided to the outlet 101 and exhausted out of the casing 10 through the outlet 101.

Please refer to FIG. 1 again. The first pressure-detecting device 14 is arranged beside the first opening 123 of the airflow-guiding member 120 for detecting the air pressure at the first opening 123. The second pressure-detecting device 15 is arranged beside the second opening 124 of the airflow-guiding member 120 for detecting the air pressure at the second opening 124.

The controlling circuit 13 is disposed within the casing 10, and connected with the first pressure-detecting device 14 and the second pressure-detecting device 15. By means of the first pressure-detecting device 14 and the second pressure-detecting device 15, the air pressure at the first opening 123 and the air pressure at the second opening 124 are realized by the controlling circuit 13. The flow rate of the second airflow T2 passing through the airflow driving device 12 may be deduced according to the following formula built in the controlling circuit 13:

${Q = {Y\sqrt{\frac{\Delta \; P}{\rho}}{\sum{CnAn}}}},$

where, Q is the flow rate of the second airflow T2 passing through the airflow driving device 12, Y is an expansion factor, ΔP is a pressure difference between the first opening 123 and the second opening 124, ρ is the air density, Cn is the flow rate coefficient at the n^(th) differential distance from the first opening 123, and An is the open area at the n^(th) differential distance from the first opening 123. In addition, Y, ρ, Cn and An are constants, and may be preset in the controlling circuit 13. In accordance with a key feature of the present invention, since the open areas of the first opening 123 and the second opening 124 are different, there is a pressure difference between the first opening 123 and the second opening 124. According to the pressures detected by the first pressure-detecting device 14 and the second pressure-detecting device 15, the controlling circuit 13 could realize the pressure difference between the first opening 123 and the second opening 124. After the pressure difference is obtained, the flow rate Q of the second airflow T2 passing through the airflow driving device 12 will be calculated according to the above formula. According to the flow rate Q, the controlling circuit 13 may perform proper actions. For example, the controlling circuit may adjust rotating speed of the motor or emit a prompt signal to notify the user that the amount of the output airflow is too high or too low.

The flow rate of the second airflow T2 is measured by using the airflow driving device having the airflow-guiding member 120. Since the open areas of the first opening 123 and the second opening 124 are different, there is a pressure difference between the first opening 123 and the second opening 124. According to the pressure difference, the controlling circuit 13 could calculate the practical flow rate of the second airflow T2 passing through the airflow driving device 12. As previously described, the conventional air conditioner use many air meters to measure the airflow velocities at many detecting points, and then the airflow velocities at these detecting points are averaged to estimate the airflow amount. By means of the air conditioner of the present invention, the airflow amount could be accurately and quickly obtained.

From the above description, the airflow driving device of the present invention has a function of measuring flow rate. Since the open areas of the first opening and the second opening are different, there is a pressure difference between the first opening and the second opening. According to the pressure difference, the controlling circuit could calculate the practical flow rate of the second airflow passing through the airflow driving device. As a consequence, the air conditioner of the present invention is capable of accurately and quickly measuring the flow rate.

While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures. 

1. An airflow driving device of an air conditioner, said airflow driving device comprising: an airflow-guiding member for receiving and guiding an airflow, wherein said airflow-guiding member comprises a first opening and a second opening, the open areas of said first opening and said second opening are different such that a pressure difference is generated between said first opening and said second opening, and a flow rate of said airflow passing through said airflow driving device is calculated according to said pressure difference.
 2. The airflow driving device according to claim 1, wherein said airflow driving device is a centrifugal fan.
 3. The airflow driving device according to claim 1, wherein the open area of said first opening is greater than the open area of said second opening so that the pressure at said first opening is lower than the pressure at said second opening.
 4. The airflow driving device according to claim 1, wherein said airflow driving device further comprises an impeller, which is arranged beside said airflow-guiding member and comprises a guiding channel and plural lateral channels, wherein said guiding channel is aligned with said second opening of said airflow-guiding member for receiving said airflow, and said lateral channels are disposed in a periphery of said impeller so that said airflow coming from said guiding channel is exhausted out of said impeller through said lateral channels.
 5. The airflow driving device according to claim 4, wherein said airflow driving device further comprises a volute, which comprises a receptacle, a third opening, an airflow path and a fourth opening, wherein said fourth opening is arranged at a first side of said volute and in communication with said receptacle, said impeller is inserted into said receptacle of said volute through said fourth opening, and said third opening is in communication with said receptacle and said airflow path so that said airflow coming from said lateral channels is introduced into said airflow path through said third opening.
 6. The airflow driving device according to claim 1, wherein said air conditioner further comprises a first pressure-detecting device, a second pressure-detecting device and a controlling circuit, wherein a first pressure at said first opening is detected by said first pressure-detecting device, a second pressure at said second opening is detected by said second pressure-detecting device, and said controlling circuit calculates said flow rate of said second airflow passing through said airflow driving device according to said first pressure and said second pressure.
 7. An air conditioner, comprising: a casing; a heat exchanger disposed within said casing for transferring heat of a first airflow and producing a second airflow; an airflow driving device for guiding said second airflow to be exhausted out of said air conditioner, wherein said airflow driving device comprises an airflow-guiding member with a first opening and a second opening, wherein the open areas of said first opening and said second opening are different; a first pressure-detecting device for detecting a first pressure at said first opening; a second pressure-detecting device for detecting a second pressure at said second opening; and a controlling circuit for calculating a flow rate of said second airflow passing through said airflow driving device according to said first pressure and said second pressure.
 8. The air conditioner according to claim 7, wherein said casing comprises an inlet and an outlet, wherein said first airflow is introduced into said casing through said inlet, and said second airflow is exhausted out of said casing through said outlet.
 9. The air conditioner according to claim 7, wherein a pressure difference is generated between said first opening and said second opening.
 10. The air conditioner according to claim 9, wherein said flow rate of said second airflow passing through said airflow driving device is deduced according to the following formula built in said controlling circuit: ${Q = {Y\sqrt{\frac{\Delta \; P}{\rho}}{\sum{CnAn}}}},$ where, Q is said flow rate of said second airflow passing through said airflow driving device, Y is an expansion factor, ΔP is a pressure difference between said first opening and said second opening, ρ is an air density, Cn is a flow rate coefficient at the n^(th) differential distance from said first opening, and An is an open area at the n^(th) differential distance from said first opening. 